S E C T I O N IV. 85 



Valvatae, Nerits, or operculated Snails. 

 7. Helmets, 8. Murices. 9. Cochlea 

 Globofe. 10. Buccina. 11. Strombi. 12. 

 Volutes. 13. Alatae, as Spiders, Devil's 

 Claws, &c. 14. Olives, or Cylindars, and 

 15. Univalve Shells, as Limpets, Vermi- 

 culi, &c. but every one of his families 

 are fo confufed, that little aid to an arrange- 

 ment can be gained from his work. 



Langlus difcufles the general fubjeft in 

 fix feftions, of which the fourth gives 

 his characleriftical notes from the whole 

 flru6ture and figure of the Shell, or from 

 the principal parts, viz. the aperture in 

 the turbinated Shells, and the beaks 

 (Umbones) in the bivalves. Other minor 

 characters are their being fulcated, fmooth, 

 &c. or from the different fituations of th^ 

 parts : And alfo negative charafters that 

 are common to other Shells, as, e. g. the 

 charafter of th^ firft clafs of Univalves is, 

 that they are not turbinated, or turned in a 

 fpiral manner ; and adds, that all characters 

 Jaid dpwn Ihould be fuch as are ftrong and 



G ^ vifible I 



